Quantum disordered ground state resilient to chemical disorder in a triangular-lattice iridate
Abstract Disorder is generally expected to destabilize quantum disordered systems such as quantum spin liquids (QSLs), yet some frustrated magnets appear to evade this tendency. We report low temperature thermodynamic, magnetometric, and muon spin relaxation measurements on single crystals of the triangular-lattice compound Ba 4 Nb 0.8 Ir 3.2 O 12 , where substantial Ir/Nb site mixing introduces chemical randomness. No signatures of long-range order or spin freezing are observed down to 20 mK. Instead, the specific heat follows a T 2 dependence and the muon relaxation rate remains temperature-independent at low temperatures. This behavior is consistent with low-energy excitations characteristic of a quantum disordered system with linearly dispersing modes. Density-functional calculations reveal preferential Nb/Ir site arrangement and site-selective Ir magnetism that preserve two-dimensional magnetic frustration despite structural disorder. These results demonstrate a correlated magnetic ground state that remains quantum disordered even in the presence of pronounced chemical randomness, pointing to a mechanism for disorder-resilient quantum magnetism in a 5 d triangular-lattice iridate.
Authors
- J. Gronemann (ORCID: https://orcid.org/0009-0002-8413-3056)
- Tino Gottschall (ORCID: https://orcid.org/0000-0002-4117-8169)
- Devashibhai Thakarshibhai Adroja (ORCID: https://orcid.org/0000-0003-2280-079X)
- Debarchan Das (ORCID: https://orcid.org/0000-0001-5453-0195)
- T. Herrmannsdörfer (ORCID: https://orcid.org/0000-0001-6706-4541)
- A. Bandyopadhyay (ORCID: https://orcid.org/0000-0001-9332-8985)
- Ola Kenji Forslund (ORCID: https://orcid.org/0000-0001-8879-7875)
- S. K. Panda (ORCID: https://orcid.org/0000-0001-6675-3396)
- S. Chattopadhyay (ORCID: https://orcid.org/0000-0001-9061-2139)
- Soumen Samanta (ORCID: https://orcid.org/0000-0002-8945-7829)
- Zurab Guguchia (ORCID: https://orcid.org/0000-0002-5498-328X)
- Jochen Wosnitza
- Ena Osmic
- Shovan Gayen
- Gohil S. Thakur
- Robert Johann Scheuermann
- Iurii Skourski
Institutions
- Uppsala University (SE)
- Rutherford Appleton Laboratory (GB)
- Bhabha Atomic Research Centre (IN)
- University of Johannesburg (ZA)
- Helmholtz-Zentrum Dresden-Rossendorf (DE)
- Paul Scherrer Institute (CH)
- Bennett University (IN)
- Lalit Narayan Mithila University (IN)
- Complexity and Topology in Quantum Matter (DE)
- Indian Institute of Science Education and Research Berhampur (IN)
- UGC DAE Consortium for Scientific Research (IN)
- Technische Universität Dresden (DE)
Publication Details
- Journal
- Communications Materials
- Published
- 2026-07-01
- DOI
- https://doi.org/10.1038/s43246-026-01247-1
- Primary Topic
- Advanced Condensed Matter Physics
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Vetenskapsrådet